refactoring, run seedlink client in thread
setting seedlink thread's deamon flag. the thread is then terminated when the GUI exits
using a lock on the stream shared by both threads to prevent possible problems
The seedlink client start with a round time in the main
the main stream is trimmed after receiving a new packet
new update_time option added to change the graphical update frequency. set default update_time to 2 seconds
remove the progressbar and the "updating logic" which are not usefull with this threaded version
remove the progressbar requirement in README
change the default title
added nearest_sample=False option while triming
fix minor bug in update time command line argument
change the default time_update to 10 second to limit CPU usage
Merge pull request #2 from megies/threading

run seedlink client in thread
remove progressbar